1. Field of the Invention
The present invention relates to a connector having shielding shell to be connected to equipment such as an inverter unit or a motor for an electric vehicle.
2. Description of the Related Art
A conventional connector used for connecting a plurality of shielded wires to equipment such as an inverter unit in an electric vehicle includes a shielding shell.
The conventional connector used for such purpose, as disclosed in JP-A-11-026093, is structured in that wire-side terminals are fixedly attached to conductors of shielded wires and retained in a housing, while a conductive connecting member is fixedly attached to a shielding layer of each shielded wire. When the connector is to be attached to equipment, the housing is plugged into a mounting hole formed in a shielding casing of the equipment, and a bracket formed in the outer circumference of the housing is fixedly connected to the outer surface of the shielding casing, and the wire-side terminals are connected to equipment-side terminals in the shielding casing. Further, the connecting member is fixed to the outer surface of the shielding casing so as to connect the shielding layer of each shielded wire to the shielding casing. Hereinafter, the conventional connector having the structure described above will be referred to as a first conventional connector.
In the first conventional connecter, however, it is necessary to repeat the process of connecting the connecting member to the shielding casing as many times as the number of shielded wires. As a solution to such a problem, a collectively-shielding structure has been considered. The collectively-shielding structure uses a non-shielded wire having no shield layer in place of each shielded wire, and uses a shielding member having a cylindrical braiding made of a metal fine line braided in a mesh like manner, in place of the shielding layer of each shielded wire. A plurality of non-shielded wires are surrounded collectively by the shielding member. According to the structure above, the step of connecting the shielding member to the shielding casing can be performed at one time. Thus, the workability is improved.
When the collectively-shielding structure is adopted, the shielding member is conductively connected to the shielding casing by: fixedly attaching the opening edge portion of the shielding member to a cylindrical shielding shell; bring a flange portion formed in the circumferential edge portion of the shielding shell into close contact to the outer surface of the shielding casing; and fixing the flange portion by bolting.
In addition, as described above, a positioning bracket projects over the outer circumference of the housing. In order to fix the bracket to the shielding casing, it is necessary to provide a notch portion in a part of the flange portion, and make the bracket project to the outside of the shielding shell through the notch portion. Therefore, the flange portion is not continuous over the whole circumference, but is disconnected in the notch portion.
As a technique for forming the shielding shell, a method using a process called deep drawing out of a metal material in a flat plate shape is adopted as follows. That is, a cylindrical portion thereof is formed gradually out of a flat plate portion, while a part of the flat plate portion is left as a flange portion. In the technique described above, the flange portion may be deformed in a curved shape in the course of working the cylindrical portion. Particularly when the flange portion has a shape that is' not continuous over the whole circumference as described previously, a curve is apt to occur and the degree of the curve becomes large.
When the flange portion is thus curved, a part of the flange portion may not come in contact with the shielding casing when the shielding shell has been attached to the shielding casing. Thus, the reliability of contact between the shielding shell and the shielding casing may be deteriorated.
Another conventional connector used for above-mentioned purpose, as disclosed in JP-A-9-161892, is structured in that a mounting hole is formed in an outer wall of a casing of the equipment, while equipment-side terminals are provided inside the casing. Wire-side fittings connected to a plurality of wires are retained in one housing, and the housing is fitted into the mounting hole. Thus, wire-side terminals are connected to the equipment-side terminals respectively. In the second conventional connector, a sealing member is provided between the inner circumference of the mounting hole and the outer circumference of the housing in order to secure waterproof inside the casing. Hereinafter, the conventional connector having the structure described above will be referred to as a second conventional connector.
In the second conventional connector, three pole terminals are disposed in a triangle, while the housing for retaining the wire-side terminals is formed to have a round outer circumference. The sealing member having an annular shape is outer-fitted to the round outer circumference of the housing.
When the terminals are disposed in a triangle as described above, it is necessary to secure a certain space in the directions of both the width and the height to dispose the terminals in the space. However, it may be considered that the equipment-side terminals are obliged to be disposed alongside due to some restriction caused by the layout of the equipment or other peripheral parts. In this case, the wire-side terminals have to be also disposed alongside. In accordance with the disposition, therefore, the housing as a whole has to be formed into a noncircular shape long from side to side, such as an elliptic shape, an oval shape or a substantially rectangular shape, and the sealing member to be attached to the outer circumference of the housing has to be also formed into a noncircular shape.
However, in the case where the outer circumference of the housing and the sealing member are formed into a noncircular shape, there is a fear that a part of the sealing member floats from the outer circumference of the housing or may be stretched excessively when the sealing member is out of circumferential position relative to the housing. Assume that the housing is fitted into the mounting hole when the sealing member is attached in such a state. In this event, the close contact state of the sealing member with the outer circumference of the housing and the inner circumference of the mounting hole (the elastic bending state of the sealing member) is not uniform in the circumferential direction. There is a fear that the reliability of the seal function deteriorates.